The present invention relates to integrated circuit memory devices, and more particularly, to non-volatile memory transistors used in integrated circuit memory devices, and to methods for fabricating the same.
Recently mixed-mounting of various types of circuits has been used for a variety of factors. For example, mixed-mounting of various types of circuits can reduce factors such as chip interface delay, cost per board area, and cost of design and development of boards.
An aspect of the present invention provides integrated circuit devices that include an integrated circuit substrate, a first capacitor element, a second capacitor element, and a non-volatile memory transistor. The non-volatile memory transistor, the first capacitor element and the second capacitor element are each formed the integrated circuit substrate. The first capacitor element comprises a first lower electrode, a first dielectric film composed of an oxide film, and a first upper electrode. The second capacitor element comprises a second lower electrode, a second dielectric film including an ONO film, and a second upper electrode. The non-volatile memory transistor comprises a floating gate, a control gate, and an intermediate insulation film located between the floating gate and the control gate. Each of the intermediate insulation film, the oxide film and the ONO film include an HTO film.
Another aspect of the present invention provides methods for manufacturing an integrated circuit device. A floating gate, a first lower electrode and a second lower electrode are formed on an integrated circuit substrate. A first thermal oxide film is formed over portions of the floating gate, the first lower electrode, and the second lower electrode. An HTO film is formed over the first thermal oxide film. A nitride film is formed to cover portions of the HTO film on the floating gate, on the first lower electrode, and on the second lower electrode. Portions of the nitride film are selectively removed to leave portions of the nitride film. A second thermal oxide film if formed over the HTO film on portions of the floating gate and the first lower electrode, and over the nitride film on portions of the second lower electrode. A control gate, a first upper electrode, and a second upper electrode are then formed.
Another aspect of the present invention provides methods for manufacturing an integrated circuit device. A floating gate, a first lower electrode and a second lower electrode are formed on an integrated circuit substrate. A first thermal oxide film is formed over a side surface of the floating gate, an upper surface of the first lower electrode and an upper surface of the second lower electrode. The first thermal oxide film becomes a component of an intermediate insulation film, a component of a first dielectric film, and a component of a second dielectric film. An HTO film is formed over the first thermal oxide film. The HTO film becomes a component of the intermediate insulation film, a component of the first dielectric film and a component of the second dielectric film. A nitride film is formed over the HTO film located above the second lower electrode. The nitride film becomes a component of the second dielectric film. A second thermal oxide film is formed over the HTO film on the side surface of the floating gate, over the HTO film on the upper surface of the first lower electrode and over the nitride film on the upper surface of the second lower electrode. The second thermal oxide film becomes a component of the intermediate insulation film, a component of the first dielectric film and a component of the second dielectric film. A control gate, a first upper electrode and a second upper electrode are formed over the integrated circuit substrate.
Aspects of the present invention can thus provide integrated circuit devices having a non-volatile memory transistor and another device element that are mounted on the same integrated circuit substrate, and a method for manufacturing the same.